Redirect to previous page after logout

Hi...

In my application when i clicks the page back button in browser it is redirecting to the previous page after logout. I cleared all the sessions and session objects.
I tried all the code:
            Session.Clear();             Session.Abandon();             Session.RemoveAll();             AcademicDetails.ClearSession();             UserDetail1.ClearSession();                         ud.ClearSession();             FormsAuthentication.SignOut();      & ...